A NULL pointer dereference vulnerability in the Qt QCborValue to JSON conversion of the Qt Core module has been discovered and has been assigned the CVE id CVE-2026-105924.
Affected versions: from Qt 5.12.0 to Qt 6.8.9, from Qt 6.9.0 to Qt 6.11.2, Qt 6.12.0
Impact: An application that decodes untrusted CBOR data with QCborValue and converts the result to JSON (QJsonValue, QJsonArray or QJsonObject) can be made to crash by specially crafted input, causing a denial of service. Depending on compiler/optimizer behavior, other memory-safety consequences are potential.
CVSS 4.0 Score: 4.3 / Medium
Vector String: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/R:U/RE:L/U:Green
Mitigation: None
Solution: Apply the following patch or update to Qt 6.8.10, Qt 6.11.3, Qt 6.12.1 or later.
Patches:
dev: https://codereview.qt-project.org/c/qt/qtbase/+/766809
Qt 6.12: https://codereview.qt-project.org/c/qt/qtbase/+/777125 or https://download.qt.io/official_releases/qt/6.12/CVE-2026-105924-qtbase-6.12.diff
Qt 6.11: https://codereview.qt-project.org/c/qt/qtbase/+/778089 or https://download.qt.io/official_releases/qt/6.11/CVE-2026-105924-qtbase-6.11.diff
Qt 6.8: https://codereview.qt-project.org/c/qt/tqtc-qtbase/+/777333 or https://download.qt.io/archive/qt/6.8/CVE-2026-105924-qtbase-6.8.diff
